<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border: solid 1px red;
        }
        /*在集合中查找某个子类*/
        /* div:nth-child(1){

        } */
        div:nth-child(2){
            position: relative;
            left:8px;
        }
        div:nth-child(3){
            position: relative;
            top: 8px;
        }
    </style>
</head>
<body>
    <!--通过元素的伪类选择器获取相同元素的某个元素-->
    <div></div>
    <div></div>
    <div></div>
</body>
</html>